Researchers from The University of Nottingham have demonstrated how a species of flatworm overcomes the ageing process to be potentially immortal. The discovery, published in the Proceedings of the National Academy of Sciences, may shed light on the possibilities of alleviating ageing and age-related characteristics in human cells.

"Asexual planarian worms demonstrate the potential to maintain telomere length during regeneration," says Dr Aziz Aboobaker from the University's School of Biology. "Our data satisfy one of the predictions about what it would take for an animal to be potentially immortal and that it is possible for this scenario to evolve. The next goals for us are to understand the mechanisms in more detail and to understand more about how you evolve an immortal animal."

Planarian worms have amazed scientists with their apparently limitless ability to regenerate. Researchers have been studying their ability to replace aged or damaged tissues and cells in a bid to understand the mechanisms underlying their longevity.

"We've been studying two types of planarian worms; those that reproduce sexually, like us, and those that reproduce asexually, simply dividing in two. Both appear to regenerate indefinitely by growing new muscles, skin, guts and even entire brains over and over again," said Aboobaker.

"Usually when stem cells divide — to heal wounds, or during reproduction or for growth — they start to show signs of ageing. This means that the stem cells are no longer able to divide and so become less able to replace exhausted specialised cells in the tissues of our bodies. Our ageing skin is perhaps the most visible example of this effect. Planarian worms and their stem cells are somehow able to avoid the ageing process and to keep their cells dividing."

One of the events associated with ageing cells is related to telomere length. In order to grow and function normally, cells in our bodies must keep dividing to replace cells that are worn out or damaged. During this division process, copies of the genetic material must pass on to the next generation of cells. The genetic information inside cells is arranged in twisted strands of DNA called chromosomes. At the end of these strands is a protective 'cap' called a telomere. Telomeres have been likened to the protective end of a shoelace which stops strands from fraying or sticking to other strands.

Each time a cell divides the protective telomere 'cap' gets shorter. When they get too short, the cell loses its ability to renew and divide. In an immortal animal we would therefore expect cells to be able to maintain telomere length indefinitely so that they can continue to replicate. Dr Aboobaker predicted that planarian worms actively maintain the ends of their chromosomes in adult stem cells, leading to theoretical immortality.

Dr Thomas Tan made some exciting discoveries for this paper as part of his PhD. He performed a series of challenging experiments to explain the worm's immortality. In collaboration with the rest of the team, he also went some way to understanding the clever molecular trick that enabled cells to go on dividing indefinitely without suffering from shortened chromosome ends.

Previous work, leading to the award of the 2009 Nobel Prize for Physiology or Medicine, had shown that telomeres could be maintained by the activity of an enzyme called telomerase. In most sexually reproducing organisms the enzyme is most active only during early development. So as we age, telomeres start to reduce in length.

This project identified a possible planarian version of the gene coding for this enzyme and turned down its activity. This resulted in reduced telomere length and proved it was the right gene. They were then able to confidently measure its activity and resulting telomere length and found that asexual worms dramatically increase the activity of this gene when they regenerate, allowing stem cells to maintain their telomeres as they divide to replace missing tissues.

Dr Tan pointed out the importance of the interdisciplinary expertise: "It was serendipitous to be sandwiched between Professor Edward Louis's yeast genetics lab and the Children's Brain Tumour Research Centre, both University of Nottingham research centres with expertise in telomere biology. Aziz and Ed kept demanding clearer proof and I feel we have been able to give a very satisfying answer."

However, what puzzled the team is that sexually reproducing planarian worms do not appear to maintain telomere length in the same way. The difference they observed between asexual and sexual animals was surprising, given that they both appear to have an indefinite regenerative capacity. The team believe that sexually reproductive worms will eventually show effects of telomere shortening, or that they are able to use another mechanism to maintain telomeres that would not involve the telomerase enzyme.

Life and death are integral to everything in existences, living thing or not,from stars to planets, to animals, to humans. Science can search as hard as it wants on this, but will never be able to change this simple truth of life.

Just by coincidence, I watched a movie called "The Man from Earth" earlier tonight on Netflix. It's about a man who reveals he's been alive for 14,000 years and doesn't age. Fairly related to this story.

I think though that there are other potential roadblocks to biological immortality. Telomeres aren't the whole story; if you could keep telomeres from shortening in humans, you would eventually die of cancer. Cell apoptosis (sp?) serves a valuable function in more complex animals, namely killing off cancer cells. The ability of cells to reproduce indefinitely is one of the hallmarks of cancer.

There are also other cellular aging mechanisms. Whenever your DNA gets damaged (cosmic rays, environmental toxins, etc.) it mostly gets repaired, but this repair process is not perfect and over time damage does accumulate. Cellular mitochondria can also degrade over time. Cells can also become less efficient at removing waste products & toxins, eventually becoming clogged with them. And if the flatworm finds itself in an environment where it is unable to get enough of an essential mineral or nutrient, that can also harm or kill it.

If we eventually want to achieve indefinite lifespans (the technically correct and de-mythologized term for "immortality"), I think we will have to move beyond biology to synthetic life. E.g. mind uploading or true AI. Biology and biochemistry have too many potential fail points to be indefinitely reliable. We're just too squishy.

@leonidas - i agree.
All this goes to prove is that a wealthy individual, is so tightly bound to the wheel at a young age - his fear will only grow worse with age - look at hollywood folk - wealth is a devastating fetter. Wealth is seen to be connected to vanity and perfection in competition.
As i say, scientists are so duff, they fail to even see
why it is the are unable to think anew, only cover that which has gone before. Creativity halts when money is involved in the reward system.
Quick question-
How huch money does a top scientist earn when he puts
in place a model such as the big bang? . when he speculates with a limited human brain?

I think this is extrodinary, we can't we live forever, we as human being ar highly advanced, we have emotions and personalitys and we loved, I personally do not see death as natural. I love my family more than anything that excists, I can't even describe in words how much they mean to me and I'm supposed to be ok with the fact that one day or any day they could die, NO! with Biological immortality or computers that can upload are brains and personalitys, or advancements in nano technologys, we will be able to be with the people that we love forever and I know that If i wa to become immortal I would never wish to die aslong as I had my family. And If scientists can live forever, who knows what else they might achieve, we could one day expand from this planet, and move somewhere else, anything is possible. I do not discredit God or Heaven but the fact remains that we do not have any proof that they excist and we live in a society were facts are they only thing that matter, so you cannot insult people for wanting to be immortal because we do not know what happens after death, so it's perfectly reasonable to want to stop it, so we don't have to face the unknown, I'm very scared of death, the thought of dying and my personality and everything that makes me, me, dissapearing, terrifies me, does that mean tha I won't live my life, no, I'll live every day to the fullest but when we do find away to stop death and I'm very confident we will, I know that I'll jump at the chance, and I'll make sure my family jump at it aswell. I really don't care what any of you think because if they do find away to stop death, then don't bother doing it if your against it, no one will force you but don't try and insult or stop people like me who are all for it. whether it's them finding away to stop are cells from dying or mind to computer uploads or nano particles relplacing are blood cells to make are body much more efficient and effectively stoping us from aging or whether it's vampires!!!! I don't care but I'm 16 and I hope that I'll get to be 16 forever, thats my dream and its not for vanity reasons, I'm really not that goodlooking and I really dont care about people appearances, I want to be immortal so that I can be with my family forever. DEATH isn't natural, how can me losing the people that I love so deeply be natural, the fact is, it isn't natural, and I can't wait for the day where my dream comes to life, I'll be with my mum forever, I don't care what it costs, my dream is worth it

The one thing most people don't seem to understand is that biological immortality doesn't provide full immortality. People would still be able to die through other natural causes, such as severe accident or injury. The only thing that biological immortality would prevent is the aging process, by reducing or eliminating the degeneration caused by cell reproduction. Death is a natural process, and it cannot be completely avoided at this time, or in the foreseeable future.

This discovery is the first stepping stone to what we can...WILL become. And then we will be able to give life back to those who have lost it. We will reach out to the stars and beyond.

"Death and life have their determined appointments, riches and honors depend upon heaven" - This phrase is bullshit. Why are death and life certain? I don't belive this, technology and science will prevail and lead us to a better tomorrow.

The game Deus Ex Human Revolution is how I see the future, Augmentations, Corporations, Science and Technology, etc.

People i think this is an unatural way to do stuff. if you think of it, wouldn't it be against natural? we have to die to give other people chance to live! imagine the world full of humans! we would destroy ourselves by global warming from something like that.

intresting data but i think for humans to become biologically immortal is not a near future thing moreover what i wondered does these teloromes are no t present in asexually reproducing organisms and if so why does they still present in the world

Think of the possibilities of an extended life, 3 or 4 different careers. Spending more time studying at University, Pursuing a sport professionally, deciding to be a writer at 125, studying medicine at 220, Intergalactic space travel is a bit useless if the crew all dies after our allotted 70 to 85 years. Our short lifespan is a handicap. Go hard you smart humans involved in cracking longevity.

Even before we have realized the possibility of living forever, those who are mired in their fear of the unknown and an unwillingness to change are fighting the inevitability of human biological immortality.

I've actually been looking into this recently and I do find it to be fascinating, I'm a 10th grader taking AP Biology and I've been looking into this. Towards the end the article it was stated that the worms "...will eventually show effects of telomere shortening..." Even if they can show it, they must still have some way of expanding their lifespan. If they don't use the Telomerase enzyme, they must use something. Keep going with this, find out how they do it and experiment. It could be possible to replicate it and create a human supplement. Loosely defined; Biological immortality means that trauma can still kill you, but you won't die of age.
DwarfGalaxy says "You probably die of boredom. If you become immortal you probably wish you could die. To have the freedom to choose is what matters most in life." If you get bored, then you still have a way out, trauma.
This concept of Biological immortality is apparently religiously controversial. Doesn't God promise eternal life? Well why wait? If i could get it without taking a bullet to the head, that would be favorable, imagine life without death. In some aspects, it would be problematic considering overpopulation, but people will still manage to die. It will be controlled somehow.
Mountainbiker states, "Our short lifespan is a handicap." It is unless we can attain this, we need more people working on this and it can be done. As soon as i graduate, maybe before, I can guarantee I'll be in this field.
Too all of the people who think it's "unnatural," you don't have to be involved, if you would like to die, then go for it, i personally would rather find a way not to.
Sorry for any grammar errors or confusion, it's 3:00 in the morning and I'm worn out. :P

To the smart ones, we must organize for this worthy cause. go to myspace, make up some BS account, and search for "Super-ego." if you see a profile picture of foggy woods, you're there. we must speak, collaborate and advance. I recommend finishing biology in school before we make any actual advances.

P.S. anyone opposed to this notion, please ignore. I do not discriminate race, religion, gender, sexual orientation, anything like that. open-mindedness and a burning desire to see this through are the only requirements.

Well for me we have to be immortal in biological way. Die from accident or disease is another thing. But this biological block has to be crack, because we human needs thousands and thousands of years to do many things. We have to be in galactic civilization, Where we can live anywhere in the universe. Using this thousands of suns as source of energy. We are living here depending on dead fossils as a energy source. We couldn't even use our unlimited source of energy "THE SUN". We are in 0 stage according to Michio Kaku, i think he makes sense. Billions of universe,with billions of suns, out there with infinite energy source. There are lots and lots and lots of things to do. The road is very very long for our human civilization to go. This human population is nothing, If we have the ability to use this universe. In our planet, we are the only creature who new our time is limit, who knew anything is not set on stone, who knew anything is possible. I think every individual deserve to live longer, let us say immortal. Because this is our universe, and we could not even move 2 steps away from our home "EARTH". With this energy of the universe feeding billions and billions of people is nothing. We need lots of things to do, And i welcome this immortality concept wholeheartedly.

Immortality seems to be the wrong word. Extreme life extention is more reasonable. Death may be natural but aging is nothing more than a disease we all have and that disease is the issue. I am all for the cureing of aging. It has been said that it is unnatural and is therefore wrong to try. I would love to see the tree they picked thier laptop from. Others point out that life after death is what god intended for us. I dont understand why those people dont kill themselves if they trully think that way. We have been endowed with large brains capable of science and therefore are obligated to advance our species as far as possible. I like modern technology and will gladly accept thousands of years of life even if its not forever.
TO ALL THE PEOPLE WOKING ON THE CURE FOE AGING: Thank you for all your tierless efforts and please ignore all the nay sayers,(fogiveness is not nessisary since they will be dead in less than 90yrs anyway).